Deltiology (from Greek δελτίον, deltion, diminuitive of δέλτος, deltos, "tablet, letter"; and -λογία, -logia) is the study and collection of postcards. Compared to philately, the iden- tification of a postcard's place and time of production can often be an impossible task because postcards, unlike stamps, are produced in a decentralised, unregulated manner. For this reason, some collectors choose to limit their acquisitions to cards by specific artists and publishers, or by time and location.

Pannonhalma is a small town in western Hungary, in Győr-Moson-Sopron county with approx. 4.000 inhabitants. It is about 20 km from Győr; it is accessible by car, bus or train.The town, known as Győrszentmárton until 1965, is dominated by its most famous landmarks: the thousand-year-old Pannonhalma Archabbey and the Benedictine Secondary School, which are situated above the village, on Szent Marton Hill. The hill itself is still known by this ancient name and the name "Pannonhalma" was introduced as part of the Hungarian language reforms in the nineteenth century. The association with Saint Martin ("Szent Márton" in Hungarian) derives from a belief that Martin of Tours was born here, though others believe he was born in nearby Szombathely.There is a small statue in the town at the crossroads under the abbey which shows the saint as a Roman soldier, cutting his cloak according to the legend associated with him. The wall behind this is part of the original fortifications which were built in 1569 as a result of incursions into Western Hungary by the Ottoman Turks. The area remained a moving frontier between the Islamic Ottoman empire and the Christian west for the following 140 years and the town suffered considerable damage during this time.From at least the nineteenth century, Szent Marton had a significant Jewish community. They played an important role in the commerce of village, as it was then, until the latter years of World War II. In 1944 the remaining Jewish families were rounded up and sent to extermination camps. A small synagogue, built in the late 1800´s, remains on the main street, though it is no longer in use. The building is in the process of being restored and a monument has been constructed on the street in front of it. Some dozens of Jews were protected in the abbey when it was taken under control of the International Red Cross in October 1944, along with 3.000 other refugees, many of them children, thanks to the efforts of a Swiss national, Eduard Benedek Brunschweiler. The IRC was expelled from Pannonhalma by the Red Army in April 1945.In 1996 parts of the town were included in UNESCO's demarcation of the Abbey as a World Heritage Site. Four years later, the village of Pannonhalma was officially granted "town" status.